Good investments provide returns, such as companies, real estate, bonds.
Gold and silver provide no returns. It's really just an inert lump of timeless metal. This physical property of the precious metals is what makes them good for certain purposes such as an insurance against currencies and financial systems crashing, which might happen once a lifetime. That's why investors keep a small percentage of their portfolio in gold, for insurance purposes.
That "once in a lifetime crash" will happen sooner than later. You will definitely be alive for it, but will you be prepared? It's all about timing... timing is everything.
Gold and silver are a store of value and wealth. Why do you think banks, governments, kings and queens hoard it?
Right now PMs are being manipulated to death by government/Wall Street bankers because they want you to use their fiat paper that constantly loses value with time. People complain about prices of goods and services going up... that's not it... the value of the currency is being devalued/debased, they made up a bogus name for it, it's called "inflation"